Aromatic dimethicone copolyol polymers as sunscreen agents in personal care applications

ABSTRACT

The present invention relates to a process for protecting hair and skin from the deleterious effects of ultra violet radiation using topical applications of a novel dimethicone copolyol compounds bearing ultra violet absorbing substituents.

RELATED INVENTION

This application is a continuation in part of co-pending U.S. application Ser. No. 09/611,553 filed Jul. 7, 2000, now U.S. Pat. No. 6,080,880.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

The present invention relates to the use of novel dimethicone copolyol compounds bearing ultra violet absorbing substituents. The compounds of the present invention are especially well suited for the photoprotection of the skin and/or the hair against the deleterious effects of UV radiation, in particular solar radiation. The present invention describes a process for the protection of hair and skin from the deleterious effects of ultra violet radiation, which comprises contacting the skin or hair with an effective UV protecting concentration of a aromatic dimethicone copolyol. The related application relates to compositions of matter comprising the above novel compounds.

2. Description of the Prior Art

It is known to this art that light radiation of wavelengths of from 280 nm to 400 nm promotes tanning of the human epidermis, and that light radiation of wavelengths more particularly of from 280 to 320 nm, i.e., UV-B irradiation, causes skin burning and erythema which can impair the development of a natural tan. For these reasons, as well as for aesthetic reasons, there is an increasing demand for means of controlling this natural tanning in order to thereby control the color of the skin. This UV-B radiation must thus be screened from the skin.

It is also known to this art that UV-A radiation, of wavelengths of from 320 to 400 nm, which tan the skin, also adversely affects it, especially in the case of sensitive skin or skin which is continually exposed to solar radiation. UV-A rays especially cause a loss in the elasticity of the skin and the appearance of wrinkles, promoting premature skin aging. Such irradiation promotes triggering of the erythemal reaction or amplifies this reaction in certain individuals and may even be the source of phototoxic or photoallergic reactions. Thus, for aesthetic and cosmetic reasons, such as conservation of the natural elasticity of the skin, for example, an ever-increasing number of individuals wish to control the effect of UV-A rays on their skin, it is desirable to also screen out UV-A radiation

A wide variety of compounds suited for photoprotection (UV-A and/or UV-B) of the skin are known to this art.

Most of these are aromatic compounds exhibiting absorption of UV radiation in the region from 280 to 315 nm, or in the region from 315 to 400 nm, or in both of these regions. There is no good way known at present to modify the absorption properties of molecules to meet the specific needs, or to combine products to cover a wide range of UV wavelengths. Products heretofore known are typically formulated into antisun or sunscreen compositions which are in the form of an emulsion of oil-in-water type (namely, a cosmetically acceptable vehicle, diluent or carrier comprising a dispersing continuous aqueous phase and a dispersed discontinuous oily phase) and which thus contain, in various concentrations, one or more conventional lipophilic and/or hydrophilic organic screening agents. These are capable of selectively absorbing harmful UV radiation of specific wavelength, depending upon structure of such screening agents (and their amounts) being selected as a function of the desired sun protection factor SPF (the sun protection factor being expressed mathematically by the ratio of the irradiation time required to attain the erythema-forming threshold with the UV screening agent to the time required to attain the erythema-forming threshold in the absence of UV screening agent).

It is a long felt need to have a sunscreening agent that can absorb ultra violet radiation at specific desired wavelengths and be soluble in water or oil. In addition, these compounds exhibiting anti-UV activity must also have good cosmetic properties in compositions comprised thereof, good solubility in the usual solvents, and in particular fatty substances such as oils and greases, as well as good resistance to water and to perspiration (remanence).

U.S. Pat. No. 6,080,880 issued Jun. 27, 2000 teaches that grafting at least one cinnamamide, benzalialonamide or benzalmalonate group onto a short-chain silicone molecule, in particular onto a linear silicone chain comprising not more than six Si atoms, novel compounds are obtained which obviate the drawbacks of the screening agents of the prior art, these novel compounds having, other than very high-performance screening properties, very good solubility in the usual organic solvents and in particular fatty substances such as oils, as well as excellent cosmetic properties, which render them particularly suitable for use as sunscreens in, or for the formulation of, cosmetic compositions suited for protecting the skin and/or the hair against the deleterious effects of ultraviolet radiation. The teachings state “and, taking account of their relatively small size, these novel compounds are easier to synthesize”.

After reviewing the teachings of U.S. Pat. No. 6,080,880 and specifically the findings that low molecular are desirable, we have surprisingly found that the making of the specific compounds of the present invention, higher molecular weight compounds can be made that have the added attributes of being able to control the UV spectra, solubility in a variety of solvents and because of their molecular weight stay on the skin surface, rather than penetrate it as is the case with low molecular weight species.

SUMMARY OF THE INVENTION

A major object of the present invention is a process for the protection of hair and skin from ultra violet radiation, which comprises contacting the skin and hair with an effective Ultra violet absorbing concentration of novel silicone compounds that contain a UV-absorber and a polar alkoxylated group. The presence of the polar alkoxylated group not only has a dramatic effect upon solubility of the sunscreen, but also shifts the UV absorption properties, making it possible to synthesize products that have a specified UV absorption property. Since UV-B is the major area that causes problems with sun tanning, the products can be customized to have the desired water or oil solubility as well as the desired UV spectra. These novel compounds can be prepared to have the desired spectra, in addition to very good solubility in fatty materials, or aqueous systems, improved cosmetic properties, and which otherwise avoid those disadvantages and drawbacks to date characterizing the state of this art. This allows for the ability to formulate products heretofore unavailable to the cosmetic chemist.

Thus, the compounds effective in the process of the current invention having the formula

wherein;

a is an integer ranging from 0 to 2000;

b is an integer ranging from 1 to 20;

c is an integer ranging from 1 to 20;

d is an integer ranging from 0 to 20;

n is an integer ranging from 10 to 20;

w is an integer ranging 0 to 20;

x is an integer ranging 0 to 20;

y is an integer ranging 0 to 20;

z is an integer ranging 0 to 20.

DETAILED DESCRIPTION OF THE INVENTION

Objective of the Invention

It is the objective of the present invention to provide process for the protection of hair and skin from the deleterious effects of ultra violet radiation, which comprises contacting the hair skin with an effective ultra violet absorbing concentration of a series of novel silicone compounds that contain a UV absorber, derived from eugenol, and a polar hydroxyl-containing group referred to herein as a dimethicone copolyol group. The dimethicone copolyol group functions not only to alter the UV absorption properties of the compounds making them acceptable UV-B screens, but also modifies the solubility of the silicone compounds making them acceptable for formulation into water, silicone and oil phases.

DETAILED DESCRIPTION OF THE INVENTION

The process for the protection of hair and skin from the deleterious effects of ultra violet radiation, which comprises contacting the hair or skin with an effective ultra violet absorbing concentration of a series of novel silicone compounds conforming to the formula;

wherein;

a is an integer ranging from 0 to 2000;

b is an integer ranging from 1 to 20;

c is an integer ranging from 1 to 20;

d is an integer ranging from 0 to 20;

n is an integer ranging from 10 to 20;

w is an integer ranging 0 to 20;

x is an integer ranging 0 to 20;

y is an integer ranging 0 to 20;

z is an integer ranging 0 to 20.

One of the inventive aspects of the present invention is not only the UV absorber of used as a raw material in the practice of the present invention is which is eugenol, but also the surprising finding that when polar grows are incorporated, in this case dimethicone copolyol groups (the group covered by subscript “c”) the UV absorption spectra shifts into the UV-B region. Or stated another way, when c is zero, the UV absorption is in the UV region. This wavelength of UV is of interest only in certain high-energy states like welding, or in high altitude applications like aerospace. Since the sunscreening wavelengths are UV-B the molecules wherein c is 0 are not effective. This incorporation of the “c” subunit also allows for the variation of solubility. If the value of “x” is high, the product will be water-soluble. If the value of “y” is high the product will be more oil soluble. If the value of “a” is high the molecule will have increased solubility in silicone. If the “d” value is high the oil solubility and increases and the product will be a wax. In short, the proper selection of compounds within the scope of the present invention will allow for customized products that vary in physical form (liquid or solid), solubility (oil, water or silicone), water resistance (remain) and UV absorbing properties. This offers the formulator latitude to make products heretofore unimaginable.

PREFERRED EMBODIMENT

In a preferred embodiment, the effective ultra violet protecting concentration ranges from 0.01 to 25% by weight.

In a preferred embodiment d is 0.

In a preferred embodiment x and y are each 0.

In a preferred embodiment x is an integer ranging from 4 to 10.

In a preferred embodiment y is an integer ranging from 0 to 10.

In a preferred embodiment wherein x is 8.

In a preferred embodiment b is an integer ranging from 2 to 10.

In a preferred embodiment b is an integer ranging from 4 to 6.

In a preferred embodiment x is 10.

In a preferred embodiment a is an integer ranging from 5 to 15.

In a preferred embodiment a is an integer ranging from 5 to 10.

In a preferred embodiment a is 9.

In a preferred embodiment d ranges from 1 to 20.

EXAMPLES Raw Materials

1. Polymer Synthesis

Preparation of Silanic Hydrogen Containing Intermediates

Silicone intermediates of the type used to make the compounds of this invention are well known to those skilled in the art. International Publication (Silicone Alkylene Oxide Copolymers As Foam Control Agents) WO 86/05411 by Paul Austin (Sep. 25, 1986) p. 16 (examples 1 to 6) teaches how to make the following intermediates, and is incorporated herein by reference.

Hydrosilylation Silanic Hydrogen Containing Compounds (Comb Type)

The polymers used as raw materials are known to those skilled in the art and conform to the following structure:

Compounds of this type are available from Siltech Corporation Toronto Ontario Canada.

Average Austin Molecular Equivalent Example Example a b Weight Molecular 1 1 20 3 1,850 551 2 4 160 5 24,158 4,831 3 6 20 10 2,258 225

Compounds of this type are also available commercially from Siltech Corporation Toronto Ontario Canada. The structures were determined using silicone NMR and the chemistries were described using experimentally determined structures. Trade names are given merely for reference.

Example Siltech Name a b 4 Siltech D-116 9 4 5 Siltech H-345 22 5 6 Siltech C-106 50 10 7 Siltech ZZ-302 70 20 8 Siltech XX-456 50 60 9 Siltech J-456 10 20 10 Siltech G-456 0 60

2. Absorber

EXAMPLE 11

The UV absorber of used as a raw material in the practice of the present invention is eugenol. Eugenol is 2-methoxy-4-(2 propenyl)phenol. It has a molecular weight of 164.20 and is commercially available from many conforms to the following structure:

As it will become clear in the invention, eugenol by itself absorbs UV in the UV-C region making it unacceptable for sunscreen applications. Only when made into a compound of the present invention are utilized does the spectra shift into the UV-B region.

3. Alkoxylated Allyl Alcohols

Alkoxylated allyl Alcohol conforms to the following structure:

CH₂═CH—CH₂—(CH₂CH₂—O)_(x)—(CH₂CHCH₃O)yH

wherein

x and y are integers independently ranging from 0 to 20.

Compounds of this type are also available commercially from Siltech Corporation Toronto Ontario Canada. The structures were determine using carbon NMR and wet analysis. The chemistries were described using experimentally determined structures. Trade names are given merely for reference.

Example x y 12 0 0 13 8 0 14 20 20 15 16 8 16 5 5 17 25 25 18 12 6 19 9 9 20 0 9

4. Alpha Olefin

Alpha olefins are items of commerce and are available from a variety of sources including Chevron. They conform to the following structure:

CH₂═CH—(CH₂)_(s)CH₃

s is an integer ranging from 8 to 50 and is equal to n−2.

Example s 21 8 22 10 23 12 24 14 25 18

4. Alpha Olefin

Alpha olefins are items of commerce and are available from a variety of sources including Chevron. They conform to the following structure:

CH₂═CH—(CH₂)_(s)CH₃

s is an integer ranging from 8 to 50 and is equal to n−2.

Example s 21 8 22 10 23 12 24 14 25 18

5. Hydrosilylation

The hydrosilylation reaction used to make the compounds of this invention is well known to those skilled in the art. One of many references is International Publication (Silicone Alkylene Oxide Copolymers As Foam Control Agents ) WO 86/05411 by Paul Austin (Sep. 25, 1986) p. 19.

General Reaction Process (Hydrosilylation)

To a suitable flask fitted with a mechanical agitator, thermometer with a Therm-o-watch temperature regulator, nitrogen sparge tube vented reflux condenser and heating mantle is added the specified quantity of eugenol (example 11), allyl alcohol alkoxylates (examples 12-20), and alpha olefin (examples 21-25) examples Next is added the specified number of grams of the specified hydrosilylation intermediate (Example # 1-10)) and isopropanol. The temperature is increased to 85 C and 3.5 ml of 3% H2PtCl6 in ethanol is added. An exotherm is noted about 95 C, while the contents are stirred for about 2 hours. During this time silanic hydrogen concentration drops to nil. Cool to 65 C and slowly add 60 g of sodium bicarbonate. allow to mix overnight and filter through a 4-micron pad. Distill off any solvent at 100 C and 1 torr.

Example 26

To a suitable flask fitted with a mechanical agitator, thermometer with a Therm-o-watch temperature regulator, nitrogen sparge tube vented reflux condenser and heating mantle is added 396.9 grams of eugenol (example 11), 915.4 grams of allyl alcohol alkoxylate (example 16), 1687.7 grams of hydrosilylation intermediate (Example # 15) and 750 grams of isopropanol.

Heat to 85 C and add 3.5 ml of 3% H 2 PtCl 6 in ethanol.

An exotherm is noted to about 95 C, while the contents are stirred for about 2 hours. During this time silanic hydrogen concentration drops to nil. Cool to 65 C and slowly add 60 g of sodium bicarbonate. allow to mix overnight and filter through a 4-micron pad. Distill off any solvent at 100 C and 1 torr.

Silanic Polymer Eugenol Allyl Alkoxylate Alpha Olefin Example Example Grams Example Grams Example Grams Example Grams 23 1 2600.8 11 233.9 12 165.2 21 0 24 2 2617.0 11 34.9 13 348.1 21 0 25 3 497.1 11 181.7 14 2321.2 21 0 26 4 703.4 11 107.9 15 2188.6 21 0 27 5 1522.5 11 238.7 16 1238.7 21 0 28 6 522.7 11 38.4 17 2438.9 21 0 29 7 423.0 11 53.0 18 2524.0 21 0 30 8 387.3 11 85.1 19 2527.6 21 0 31 9 543.5 11 211.8 20 2244.7 21 0 32 10 1360.6 11 592.0 12 1046.6 21 0 33 1 2064.2 11 185.6 13 463.5 21 286.6 34 2 1942.5 11 25.9 14 991.7 22 39.9 35 3 691.9 11 101.1 15 2050.9 23 156.1 36 4 1223.6 11 187.7 16 1298.7 24 289.8 37 5 607.9 11 47.7 17 2270.9 25 73.6 38 6 1229.4 11 90.3 18 1540.8 21 139.4 39 7 886.1 11 66.6 19 1978.8 22 68.5 40 8 581.7 11 63.9 20 2255.8 23 98.6 41 9 1589.3 11 371.7 12 656.4 24 382.5 42 10 429.1 11 93.4 13 2333.2 25 144.3 43 1 1261.7 11 113.5 14 1449.7 21 175.2 44 2 2430.1 11 32.4 15 437.6 22 99.9 45 3 1038.5 11 151.8 16 1575.3 23 234.4 46 4 478.9 11 73.5 17 2334.1 24 113.4 47 5 1182.4 11 92.7 18 1581.8 25 143.1 48 6 1201.7 11 88.3 19 1573.8 21 136.3 49 7 1209.9 11 90.9 20 1605.6 22 93.6 50 8 1799.5 11 197.6 12 697.9 23 305.0 51 9 665.1 11 103.7 13 2071.2 24 160.1 52 10 123.1 11 53.6 14 2740.5 25 82.8 53 4 1066.0 11 164.0 13 1228.0 21 0 54 4 534.0 11 164.0 13 409.0 21 0 55 4 355.0 11 164.0 13 136.0 21 0 Comparison Compound (no allyl alkoxylate group) 56 4 267 11 164 13 0 21 0

Applications Examples

The effectiveness of the technology of the current invention can be demonstrated by the comparison of a very simple system. The following comparison is a common silicone backbone, with differing, “b”, and “c” values. The effect upon solubility at 5% in water and the UV maxima for the absorption are quite dramatic.

Example a b c d x y z UV Absorption Water Solubility 53 9 1 3 0 8 0 0 325 nm (UV-B) Soluble 54 9 2 2 0 8 0 0 320 nm (UV-B) Dispersible 55 9 3 1 0 8 0 0 312 nm (UV-B) Dispersible

Comparison Compound

Example a b c d x y z UV Absorption Water Solubility 56 9 4 0 0 8 0 0 280 nm (UV-C) Insoluble

It is most interesting and significant that the compound of example 56 has no dimethicone copolyol groups present in the molecule, but has the eugenol based UV absorber. The absorption is at 280 nm which is the UV-C spectrum. This wavelength is too low to be of interest in sun protection. UV-C is filtered out by the atmosphere and is of concern only at levels above 20,000 feet and in certain high energy situations like welding. The result is that the compound covered by example 56 is not a sunscreen. The making of compounds of the present invention, that is incorporation of polar dimethicone copolyol groups into the molecule results in a shifting of the spectra into the UV-B region (290-320 nm).

The compounds of the present invention as demonstrated in the above simple system allows one to tailor the compound to cover a wide range of wavelengths, or by blending cover a broad spectrum of wavelengths. The incorporation of FDA approved sunscreen agents into emulsions that contain the compounds of the present invention are used as auxiliaries and or emulsifiers is expected to give the optimum performance.

In addition the compounds of the present invention can be placed on textile fabrics, commonly canvas as used in commercial awnings. The compounds would not only render the canvas soft, but also provide protection over a wide range of UV conditions.

Another application is to use the compounds of the present invention to soften garments. This would not only protect the garment from UV degradation, but also provide the wearer of the shirt a level of sun protection.

While the invention has been described in terms of various preferred embodiments, the skilled artisan will appreciate that various modifications, substitutions, omissions, and changes may be made without departing from the spirit thereof. Accordingly, it is intended that the scope of the present invention be limited solely by the scope of the following claims, including equivalents thereof. 

What is claimed is:
 1. A process for the protection of hair and skin from ultra violet radiation which comprises contacting the skin and hair with an effective ultra violet absorbing concentration of novel silicone polymer conforming to the following structure:

wherein;

a is an integer ranging from 0 to 2000; b is an integer ranging from 1 to 20; c is an integer ranging from 1 to 20; d is an integer ranging from 1 to 20; n is an integer ranging from 10 to 20; x is an integer ranging 0 to 20; y is an integer ranging 0 to 20; z is an integer ranging 0 to
 20. 2. A process of claim 1 wherein n is
 15. 3. A process of claim 1 wherein n is
 17. 4. A process of claim 1 wherein n is
 11. 5. A process of claim 1 wherein b is an integer ranging from 5 to
 10. 6. A process of claim 1 wherein b is
 4. 7. A process of claim 1 wherein n is
 13. 8. A process of claim 1 wherein a is
 9. 